SALIVARY GLANDS OF MAMMALS. 403 



jubata ; and there is a superadded aggregate of mucous follicles 

 behind the eyeball, in the shallow orbit of the smaller species, the 

 secretion of which enters near the angle of the mouth. 



In the Hyrax the parotid exceeds the submaxillaiy in size, 

 and is of a redder colour : the sublinffiial is almost as laro'e as 



o 



the latter. In the Horse the parotid forms a considerable mass 

 extending from its normal position behind the masseter, upward 

 to the ear-conch, the base of which it embraces, and downward to 

 the larynx, where it meets its fellow. Three ducts quit the mass 

 at different points of its lower half, converge and unite as they 

 pass downward and forward ; the common duct, which curves 

 down beneath the lower border of the masseter, rises in front of 

 that muscle to pierce the buccal membrane at a papilla opposite 

 the last upper premolar. The submaxillaries are about one-fourth 

 the size of the parotids, by which they are covered : the gland 

 extends from the transverse process of the atlas to the angle of 

 the jaw. The duct terminates on a valvular papilla anterior to 

 the fraenum linguae. The sublingual glands, beneath the sides of 

 the fraenum, are elongate, as large as the submaxillaiy, and 

 communicate with the mouth by several orifices. The buccal 

 glands form large tracts of lenticular follicles along the upper 

 maxillary bone, ascending to beneath the zygoma. 



In the Hog-tribe the parotids have a large proportional size : 

 the duct follows the lower border of the masseter, curves upward, 

 and opens into the mouth opposite the last premolar : there is a 

 small patch of buccal glands near its termination. In the Baby- 

 roussa and Wart-hog the parotid extends from its normal position, 

 downward and backward, to the shoulder-joint and, mesiad, to the 

 sterno-thyroids : resembling in size, shape, and proportion, the 

 siibmaxillary of the Armadillo : its duct crosses the upper part 

 of the masseter. As in the Hog, there are two sublingual 

 glands ; one, which is very long and narrow, accompanies the 

 duct of the submaxillaiy gland, and is composed of small lobes of 

 a pale reddish colour ; the orifice of its excretory duct is near 

 that of the maxillary. The second sublingual gland is placed in 

 front of the former, and is of a square form; it discharges its 

 secretion through eight or ten short ducts, which pierce the 

 mucous membrane of the mouth. Dr. Ward has given an illus- 

 tration, fig. 304, from a preparation by Quekett, of the distri- 

 bution of the capillaries in the parotid of a Pig. The arteries 

 penetrate the areolar tissue at different points of the surface, and 

 are conducted, as it were, by this tissue through the interlobular 

 spaces as far as the primary aggregations of the vesicles, where 



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